COVID-19 as a Trigger for De Novo Crohn's Disease

Mendelian randomization and Bayesian model averaging of autoimmune diseases and Long COVID

Background

Following COVID-19, reports suggest Long COVID and autoimmune diseases (AIDs) in infected individuals. However, bidirectional causal effects between Long COVID and AIDs, which may help to prevent diseases, have not been fully investigated.

Methods

Summary-level data from genome-wide association studies (GWAS) of Long COVID (N = 52615) and AIDs including inflammatory bowel disease (IBD) (N = 377277), Crohn's disease (CD) (N = 361508), ulcerative colitis (UC) (N = 376564), etc. were employed. Bidirectional causal effects were gauged between AIDs and Long COVID by exploiting Mendelian randomization (MR) and Bayesian model averaging (BMA).

Results

The evidence of causal effects of IBD (OR = 1.06, 95% CI = 1.00-1.11, p = 3.13E-02), CD (OR = 1.10, 95% CI = 1.01-1.19, p = 2.21E-02) and UC (OR = 1.08, 95% CI = 1.03-1.13, p = 2.35E-03) on Long COVID was found. In MR-BMA, UC was estimated as the highest-ranked causal factor (MIP = 0.488, MACE = 0.035), followed by IBD and CD.

Conclusion

This MR study found that IBD, CD and UC had causal effects on Long COVID, which suggests a necessity to screen high-risk populations.

COVID-19 impact in Crohn’s disease patients submitted to autologous hematopoietic stem cell transplantation

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 is the virus responsible for coronavirus disease 2019 (COVID-19), a disease that has been blamed for inducing or exacerbating symptoms in patients with autoimmune diseases. Crohn's disease (CD) is an inflammatory bowel disease that affects genetically susceptible patients who develop an abnormal mucosal immune response to the intestinal microbiota. Patients who underwent hematopoietic stem cell transplantation (HSCT) are considered at risk for COVID-19.

AIM

To describe for the first time the impact of COVID-19 in CD patients who had undergone autologous, non-myeloablative HSCT.

METHODS

In this descriptive study a series of 19 patients were diagnosed with positive COVID-19. For two patients there were reports of the occurrence of two infectious episodes. Parameters related to HSCT, such as time elapsed since the procedure, vaccination status, CD status before and after infection, and clinical manifestations resulting from COVID-19, were evaluated.

RESULTS

Among the patients with COVID-19, three, who underwent Auto HSCT less than six months ago, relapsed and one, in addition to the CD symptoms, started to present thyroid impairment with positive anti-TPO. Only one of the patients required hospitalization for five days to treat COVID-19 and remained in CD clinical remission. Nine patients reported late symptoms that may be related to COVID-19. There were no deaths, and a statistical evaluation of the series of COVID-19 patients compared to those who did not present any infectious episode did not identify significant differences regarding the analyzed parameters.

CONCLUSION

Despite the change in CD status in three patients and the presence of nine patients with late symptoms, we can conclude that there was no significant adverse impact concerning COVID-19 in the evaluated patients who underwent HSCT to treat CD.

Autoimmune and Autoinflammatory Connective Tissue Disorders Following COVID-19

Importance

Multiple cases of autoimmune and autoinflammatory diseases after COVID-19 have been reported. However, their incidences and risks have rarely been quantified.

Objective

To investigate the incidences and risks of autoimmune and autoinflammatory connective tissue disorders after COVID-19.

Design, Setting, and Participants

This was a retrospective population-based study conducted between October 8, 2020, and December 31, 2021, that used nationwide data from the Korea Disease Control and Prevention Agency COVID-19 National Health Insurance Service cohort and included individuals who received a diagnosis of COVID-19 via polymerase chain reaction testing and a control group with no evidence of COVID-19 identified from National Health Insurance Service of Korea cohort. Data analysis was conducted from September 2022 to August 2023.

Exposures

Receipt of diagnosis of COVID-19.

Main Outcomes and Measures

The primary outcomes were the incidence and risk of autoimmune and autoinflammatory connective tissue disorders following COVID-19. A total of 32 covariates, including demographics, socioeconomic statuses, lifestyle factors, and comorbidity profiles, were balanced through inverse probability weighting. The incidences and risks of autoimmune and autoinflammatory connective tissue disorders were compared between the groups using multivariable Cox proportional hazard analyses.

Results

A total of 354 527 individuals with COVID-19 (mean [SD] age, 52.24 [15.55] years; 179 041 women [50.50%]) and 6 134 940 controls (mean [SD] age, 52.05 [15.63] years; 3 074 573 women [50.12%]) were included. The risks of alopecia areata (adjusted hazard ratio [aHR], 1.12; 95% CI, 1.05-1.19), alopecia totalis (aHR, 1.74; 95% CI, 1.39-2.17), antineutrophil cytoplasmic antibody-associated vasculitis (aHR, 2.76; 95% CI, 1.64-4.65), Crohn disease (aHR, 1.68; 95% CI, 1.31-2.15), and sarcoidosis (aHR, 1.59; 95% CI, 1.00-2.52) were higher in the COVID-19 group. The risks of alopecia totalis, psoriasis, vitiligo, vasculitis, Crohn disease, ulcerative colitis, rheumatoid arthritis, adult-onset Still disease, Sjögren syndrome, ankylosing spondylitis, and sarcoidosis were associated with the severity of COVID-19.

Conclusions and Relevance

In this retrospective cohort study, COVID-19 was associated with a substantial risk for autoimmune and autoinflammatory connective tissue disorders, indicating that long-term management of patients with COVID-19 should include evaluation for such disorders.

Case report: Immunological characteristics of de novo ulcerative colitis in a child post COVID-19

The pathological mechanisms of de novo inflammatory bowel disease (IBD) following SARS-CoV-2 infection are unknown. However, cases of coexisting IBD and multisystem inflammatory syndrome in children (MIS-C), which occurs 2-6 weeks after SARS-CoV-2 infection, have been reported, suggesting a shared underlying dysfunction of immune responses. Herein, we conducted the immunological analyses of a Japanese patient with de novo ulcerative colitis following SARS-CoV-2 infection based on the pathological hypothesis of MIS-C. Her serum level of lipopolysaccharide-binding protein, a microbial translocation marker, was elevated with T cell activation and skewed T cell receptor repertoire. The dynamics of activated CD8⁺ T cells, including T cells expressing the gut-homing marker α4β7, and serum anti-SARS-CoV-2 spike IgG antibody titer reflected her clinical symptoms. These findings suggest that SARS-CoV-2 infection may trigger the de novo occurrence of ulcerative colitis by impairing intestinal barrier function, T cell activation with a skewed T cell receptor repertoire, and increasing levels of anti-SARS-CoV-2 spike IgG antibodies. Further research is needed to clarify the association between the functional role of the SARS-CoV-2 spike protein as a superantigen and ulcerative colitis.

A complicated case of terminal ileitis post-COVID-19 infection requiring bowel resection

Since the beginning of the COVID-19 pandemic, there have been reports of children developing systemic hyperinflammatory response to COVID-19 infection, known as Paediatric Inflammatory Multisystem Syndrome Temporally associated with SARS-COV-2 (PIMS-TS). Here we would like to discuss a case of a 15-year-old male with PIMS-TS presenting as complicated terminal ileitis, requiring ileocaecal resection. Histopathologic findings of the ileocaecal specimen revealed thickened bowel mucosa, with features of granulomatous inflammation similar to Crohn’s disease, without features of intestinal vasculitis or viral particles. His post-operative course was complicated by fresh rectal bleeding, requiring urgent blood transfusion and endoscopy. Source of bleeding was not identified and his bleeding self-resolved. Gut biopsies of the remaining bowel taken during endoscopy were normal. Although this case suggests that the inflammatory process is focal to the terminal ileum with a good short-term prognosis, further follow-up is required to assess for long-term effects and risks of bowel disease.